To the north of Lies lies the Koegelwieck, the largest secondary dune valley of Terschelling, created during a large drift period on the island in the 19th century. It has an enormous wealth of plants and is therefore a protected nature reserve. There are several hiking trails through the vulnerable area, so you can fully enjoy this beautiful part of Terschelling. In winter, a lot of dune water remains here, making the paths inaccessible. Sometimes whole areas of adjacent forest are under water, where even the islanders participants in 'the Terschelling survival' can make a mistake!